In the course of their production, photographic materials are typically chilled and stored in the gelled state following preparation in order to prevent qualitative degradation. It is then necessary to liquefy, temper and degas the gelled materials so that they can be coated onto a film or paper support. Tempering should be understood hereinafter to mean the adjusting of the liquefied photographic materials to a desired temperature. Gelled photographic materials include aqueous or solid based photosensitive or nonphotosensitive emulsions or dispersions.
In order to coat the gelled photographic materials onto a film or paper support, the materials must be liquefied, degassed and tempered. Many methods are known in the prior art for liquefying photographic materials. These schemes include batchwise and continuous methods. Conventional batch systems generally involve a kettle for liquefying the gelled material and then an ultrasonic debubbler for removing the gas within the liquefied material. In a continuous system for liquefying and degassing gelled material, the material is liquefied in a heat exchanger and then degassed in a centrifugal degasser.
However, none of the prior art methods liquefies the gelled photographic material while simultaneously degassing and tempering the gelled photographic material. The present invention liquefies, degasses and tempers the material in a single operation, and in such a manner that each increment of photographic material is subjected to the same thermal history.